Tube forming machine with longitudinally movable core



Apm'ifl 25 R950 A. K. NOWAK 5 TUBE F-9RMING MACHINE WITH LONGITUDINALLY MOVABLE CORE Filed June 26, 1947 7 Sheets-Sheet l Apwifl 25, WW A. K. NOWAK 295055718 TUBE FORMING MACHINE WITH LONGITUDINALLY MOVABLE CORE Filed June 26, 1947 7 Sheets-Sheet 2 TUBE FORMING MACHINE WITH LONGITUDINALLY MOVABLE CORE Filed June 26, 1947 7 Sheet s-Sheet 4 fi0622i071" April 25, 1950 A. k. NO'WAK 2,505,718

TUBE FORMING MACHINE WITH LONGITUDINALLY MOVABLE CORE V g/ a izw/zz'o r April 1950 A. K. NOWAK 2,505,718

TUBE NALLY r A K NOWAK 2,505,718

TUBE FORMING MACHINE WITH LONGITUDINALLY MOVABLE CORE 7 SheetsSheet 7 Flled June 26 1947 Patented Apr. 25, 1950 TUBE FORMING MACHINE WITH LONG!- 'IIJULNALLY iVlUVABLE CORE Alois K. Nowak, Evanston, 111., assignor to Clearing Macnnie uurporauon, Unicago, 111., a corporation of mines Application June 26,1947, Serial No. 757,194

11 Claims.

This invention relates in general to tube forming machines wherein a blank sheet of material is formed into tubular shape.

An important object of the invention is to provide a new and novel machine wherein a blank sheet of material is formed into a tubular shape having a longitudinal gap, the resulting gap being straight and uniform along its length and in a true axial direction, whereby the gap may be welded easily and quickly by a'welclmg apparatus of conventional design.

Another important object is to provide an improved tube forming machine to neutralize the stress of the blank metal sheet by a preforming operation, after which the preformed blank is formed into a tubular shape.

A further object of the invention is the provision of a tube forming machine embodying novel characteristics wherein a die is utilized for preforming a blank sheet of material, the preformed blank being subsequently formed into a tube around a core, and then automatically stripped from the core; means also being provided for feeding automatically the next succeeding blank to the die.

Numerous other objects and advantages of the invention will become more apparent upon reading the following description taken in conjunc tion with the accompanying drawings in which:

Fig. 1 is a front elevational view of the machine of the present invention;

Fig. 2 is a side elevational view of the machine showing that side where the feeding of the blanks takes place;

Fig. 3 is a side elevational view of the opposite side of the machine where the stripping of the tube from its core takes place; Fig. 4 i an enlarged vertical transverse sectional view through the machine at substantially the center thereof showing the various parts of the machine in their relative positions when the blank sheet of material is in place;

Fig. 5 is a view similar to Fig. 4, but showing the various parts in their relative positions for the preforming step;

Fig. 6 is a view similar to Figs. 4 and 5, but showing the relative positions of the various parts immediately prior to the actual tube forming step; and

Fig. '7 is a view similar to Figs. 4, 5 and 6, but showing the various parts of the machine in their relative positions at the end of the tube forming operation.

Fig. 8 is an enlarged vertical sectional view taken substantially along the line B8 of Fig. 3,

showing the various parts of the machine in their respective positions after the tube has been stripped from its core and with the core in the machine ready for the tube forming operation.

Machines using a mandrel, or core, around which the tube blank may be pressed to form a tube have been used heretofore, but the products resulting from the use of such conventional macrimes have not been too satisfactory. These conventional machines ordinarily have, what may be termed a single point contact against the tube blank which may, in some instances, permit a shifting of the tube blank, whereupon the finished tube is not uniform throughout its length. Furthermore, flat spots on the tube are apt to occur, and the gap between the sides of the tube usually is not uniform.

It is customary in machines for forming a tube with a gap, to deliver the formed tube to a welding machine for the purpose of welding shut the gap to complete the tube. Welding machines are customarily of an automatic nature, and the welding process should take place in a straight line in an axial or longitudinal direction. Obviously, if the gap in the tube does not extend in a true axial direction, then the welding of the gap will not be uniform, and one end thereof may result in the entire absence of a weld. It is further necessary that the resulting gap be of a uniform width throughout its length and the edges of the gap must be parallel. Such uniform results have not been found to occur in tube forming machines heretofore known, and these and other disadvantages have been overcome in the use of the machine of the present invention, the preferred form of which is illustrated in the accompanying drawings.

Briefly described, the present invention involves the use of a suitable machine wherein a die block, composed of two pivotally mounted jaws, is adapted to have a tube blank applied thereto. A movable die head is so constructed that a blank will be preformed when the die head is brought into contact with the tube blank whereby a neutralization of the stresse results, the metal tending to flow somewhat during the preforming period on the blank. After this preforming step, a core is positioned above the preformed blank, and the jaws of the die block are caused to press the blank around the core to thus complete the tube forming operation. Novel means are provided to strip the tube automatically from its core and deposit another blank on the die block.

The preferred form of the machine for carryadapted to be moved into contact with the die block 4 as the head 3 moves downwardly. The entire machine, or press, may be operated preferably by suitable hydraulicmeans (not shown) but which is adapted to actuate a piston within a cylinder 3. Any suitable and well known hydraulic system may be utilized for actuating the press, and this system may consist merely of a suitable source of supply of hydraulic fluid which is caused to flow under pressure against the piston in the cylinder 8 to move the head 3 downwardly. The reverse movement of the head 3 also may take place by any suitable means, either by hydraulic pressure in the opposite direction or by pneumatic pull-back means. A control panel 3 may contain suitable control means for controlling the flow of the hydraulic liquid for the actuation of the machine or press.

One side of the machine or press is provided with suitable means for supporting a stack of tube blanks. These blanks, if desired, may be fed to the machine by hand, but preferably, they are fed automatically by means presently to'be described. The various elements at the one side of the machine include a frame or rack ill for movably supporting a table II. The table is adapted to be supported by and moved in a vertical plane by the pedestal 12 which may be :Tctuated by either mechanical or hydraulic means. The pedestal l2, for elevating the table ii, may be of any suitable construction to cause the table Ii to be elevated automatically a predetermined distance as the tube blanks are fed therefrom so that the uppermost blank is always in a position to be fed into the press by automatic means hereinafter described.

The side of the machine opposite from that Just above described and as shown in Figs. 1 and 8, has a shuttle member l4 which carries a core II at the underside thereof and this core is adaptedto be reciprocated longitudinally from the position shown in Fig. 1 to a position immediately below the head of the press. One end of the shuttle I4 may have secured thereto an outwardly and downwardly extending arm i6 which has a shoe, or other suitable means, l1 attached to its outer end. The shoe H is adapted to contact one end of a blank l3, (as shown in Fig. 8 and in the dotted line position thereof in Fig. l), and to move the blank to its position on the die block 4 within the press, as shown in the full line position thereof in Fig. 1. Thus, as the shuttle 14 moves toward the right, from its full line position shown in Fig. 1, the shoe I! will move toward the right and will become positioned at the righthand end of the uppermost blank l3. As the shuttle l4 then moves back toward the left, (to its full line position shown in Fi 1) the movement oi the shoe i'l will carry with it the uppermost or next succeeding tube blank i3 and position such blank on the die block 4.

The shuttle l4 normally is mounted and adapted tomove within the die member I, but the shuttle also may have auxiliary supporting means It extending outwardly from the machine, said 4 means.being supported in turn by the supporting links i The formed tube, on the core I3, is carried outwardly to the full line position thereof as shown in Fig. 1 at the completion of the ilnal forming operation. Suitable means are then provided to strip the tube from its core as the shuttle moves back to its operative position within the press, at which time the tube will drop downwardly to a suitable rack 20, whereupon the tube in its final form may be then placed on a suitable conveyor 22 where it will be directed to a continuous seam welding machine for welding the gap therein.

Thus far a general description of the operation of the machine has been given as well as the details of the varioussteps involved. The manner in which the previously mentioned advantages enumerated above may be achieved, will now be described by reference to Figs. 4 through 7. The die block 4, Fig. 4, is composed of oppositely disposed jaw members 23 and 24 which are pivotally connected together at their centers by means of an elongated rod or shaft 25. These jaw members may extend substantially the width of the press and are of sufllcient length to support the entire length oi the tube blank l3. The inner sides of the jaws 23 and 24 are provided with elongated inwardly extending arcuate surfaces or recesses 26 and 21, and the tube blank 13, when in place, is adapted to rest at three points along its length. The two jaws are so formed as to support the tube blank l3 at its center, and these laws are preferably provided with elongated recesses 28 and 29 for the purpose of receiving the longitudinal edges of the tube blank.

A cushion plunger 3a is mounted for vertical reciprocation within the bed I, the plunger being provided at its upper end with an elongated supporting member 3| having an insert 32. The insert 32 is provided with a longitudinal concave portion 33 adapted to support the undersides of the jaws 23 and 24 at their longitudinal centers.

The undersides of the jaws are also supported along eachside of the center by elongated supporting blocks 34 and 35 which are adapted to be received in'longitudinal arcuate recesses 36 and 31 provided in a suitable portion of the bed I. The upper sides of the supporting blocks 34 and 35 are longitudinally concave as indicated at 33 and 39 for the purpose of providing a sturdy support for the 'under curved sides of the jaws 23 and 24.

The movable die member 'i is provided with spaced elongated downwardly extending legs 40 and 4i, each oi. which is arcuately shaped at its lower side as indicated at 42 and 43, respectively. The space 44 between the two legs 40 and 4| is so shaped as to receive slidably theshuttle I4 which is shown in Fig. 4 in its outer position, and as 11- lustrated in full lines in Fig. l.

The first step in the operation of the machine is the preforming of the tube blank, and for this purpose the head 6, carrying the die member i, is moved downwardly to the position shown in- Fig 5. The shuttle i4 and core l5 will not interfere with such movement because these members are not within the press during the preforming operation. The legs 40 and 4| of the die member i are adapted to bear against the blank l3 to press the sides thereof into the recesses 26 and 21 of the Jaws 23 and 24. This preforming step neutralizes the stress present in the blank, and causes the material to flow so that the final forming step may take place more readily and allowthe sap to be formed in a true axial direction with the sides thereof in parallel relationship.

After the preforming step has taken place, as

the center line of the preformed blank it, further downward movement of the head forcing the cushion plunger 30 downwardly. The downward movement of the plunger 30 permits downward movement of the pivot 25 which carries with it the jaws 23 and 24. The outer surface of the laws, however, are more or less in a fixed position so that downward movement causes the jaws to close, as shown in Fig. 7. The closing of the jaws 23 and 24 also causes a rotation of the supporting blocks 34 and 35 in the manner shown. The completed tube 2| is thus formed by being pressed around the core l5, whereupon the head 6 is elevated, permitting the jaws to open.

Any suitable means may be provided to assure the re-opening of the jaws, but the preferred form of the device is illustrated herein as including a pneumatic pull-back cylinder 45 at one side of the die block. The cylinder 45 has a piston arranged therein to which a piston rod 46- is connected. A link 41 connects the outer end of the piston rod 46 to a bracket 48 which is secured to the jaw 23. This pneumatic pull-back arrangement normally will urge the jaws to an outward position; and as the head is elevated after the final forming of the tube, thus permitting the cushion plunger 30 and pivot shaft 25 to also move upwardly, the pneumatic pull-back will act to assure that the two laws will return to their normal open positions, as shown in Fig. 4, for the reception of a next succeeding blank.

After the head, and die member I carried thereby, are elevated after the final step, the shuttle I4 is then moved out of the press to its full line position shown in Fig. 1; and as this movement of the shuttle occurs, the feeding means It and I! will automatically feed the next succeeding blank into the die block in the manner described hereinbefore.

Movable end brackets 49 and 50, Fig. 3, are provided, and these brackets may be opened, as shown in Fig. '7, and closed at suitable fimes during operation of the machine for stripping the tube from its core. After the shuttle reaches its outermost position, the brackets 49 and 50 are then moved to closed position where the inner ends thereof bear against the innermost end of the tube 2| just formed. The shuttle remainsin this position during the preforming operations, Figs. 4 and 5, after which time the shuttle is brought back within the press to the position shown in Fig. 6. During this movement of the shuttle, the brackets 49 and 50, while permitting movement of the core, will restrain the tube II, and thus, strip the tube from the core, whereupon the tube will drop into the rack 20. The tube may then be removed from the rack and placed on the conveyor 22 where it will be carried to a continuous seam welding machine for welding the gap to complete the final tube. v i

The tube formed, in the manner just described, will be free from flat spots, and the gap will be uniform and will extend in a true axial direction. The numerous disadvantages inherent in usual and conventional tube forming machines are thereby overcome. The preforming operation on the tube blank, in a sense, conditions the matetube.

It will be evident that numerous changes may I be made in the form, construction and arrangement of parts from that disclosed herein without in any way departing from the spirit of the invention or sacrificing any of the attendant advantages hereof. For example, diflerent speciilc means can be used for feedingthe blanks into the press, and the specific means for stripping the tube described herein may be modified as well. Certain of the actions described in the' operation of the machine may be hydraulically controlled and others may be mechanical, the invention residing in the apparatus for carrying out the various operations disclosed.

Having thus described my invention what I claim as new and desire to secure by Letters Patent of the United States is:

1. A tube forming machine comprising a die block adapted to support a tube blank, an elongated core member movable into and out of the machine, means for pressing the tube blank around said core while in the machine to form the tube, means for stripping the formed tube from said core, and means operable by movement. of said core member out of the machine to feed the next succeeding blank to said die member.

2. A tube forming machine comprising a die block adapted to support a tube blank, means for preforming the tube blank into a predetermined contour, an elongated longitudinally movable core, meansfor pressing the preformed tube blank around said core to form the tube, means for stripping the tube from said core, and means operable upon movement of said core in one direction to feed the next succeeding blank to said die member.

3. A tube forming machine comprising a die block adapted to support a tube blank, an elongated movable core mounted for movement longitudinally and transversely thereof, means for moving said core to a position adjacent said die block, means for pressing said blank around said core while in the machine to thereby form the tube, and means for moving said core with the tube formed thereon away from said die block, whereby the tube may be stripped therefrom.

4. A tube forming machine comprising a die block adapted to support a tube blank, an elongated core mounted for longitudinal movement into and out of the machine adjacent said die block, and means for pressing said blank around said core while in the machine to thereby form the tube, said core being movable with the tube thereon out of the machine, whereby the tube may be stripped therefrom.

5. A tube Iorming machine comprising a die block adapted to support a tube blank, an elongated core mounted for longitudinal movement into and out of the machine, means for pressing said blank around said core while in the machine to thereby form the tube, said core being movable with the tube thereon out of the machine, and means operabl by movement of said core out of the machine to feed a succeeding blank to said die block.

6. A tube forming machine comprising a die block adapted to support a tube blank, an elongated core mounted for longitudinal movement into and out of the machine, means for pressing said blank around said core while in the machine to thereby form the tube, said core being movable with the tube thereon out of the machine, and

rial to facilitate the forming of the completed,

aaoema sectional contour when said core is out of themachine, and means for pressing the preformed blank around said core when it is in the machine, to thereby complete the formation of the tube.

8. A tube forming machine comprising a die block adapted to support a tube blank, an elongated core mounted for movement into and out of the machine, means for preforming the tube blank into a predetermined cross-sectional contour when said core is out of the machine, means for pressing the preformed blank around said core when said core is in the machine to thereby form the tube, means operable upon movement of said core out of the machine to feed a succeeding blank to said die block, and means for stripping the tube from said core upon the next movement of said core into the machine.

9. In a tube forming machine of the character described, a die block including a pair of jaws each having a recess therein, a complementary die member including a pair of spaced legs, said die block adapted to support a tube blank, means to cause a relative movement between said die block and complementary die member toward each other under pressure to thereby preform the tube blank by pressing the sides thereof into the jaw recesses, a core normally out of the machine but movable longitudinally into the machine after the preforming operation and positioned above the preformedblank, and means to press the preformed tube blank around said core, to thereby complete the forming of the tube.

10. In a tube forming machine of the character described a die block including a pair of pivotally mounted jaws each having an elongated recess therein, a complementary die member including a pair of spaced legs adapted to be received by said recesses, means on said die block to support a tube blank, means to cause a relative movement between said die block and complementary die member toward each other under pressure to thereby preform the tube blank by pressing the sides thereof into the jaw recesses, a core nor- 50 Number Name Date 1,045,089 Belding Nov. 19, 1912 1,258,892 Griffin Mar. 12, 1918 1,497,006 Aikens June 10, 1924 1,607,073 Gros Nov. 16, 1926 1,633,744 Hughes June 28, 1927. 1,698,904 Baker Jan, 15, 1929 1,849,054 Boisson Mar. 15, 1932 1,852,101 Baker Apr. 5, 1932 1,879,078 Carlsen Sept. 27, 1932 1,888,380 Free Nov. 22, 1932 1,912,000 Kloss May 30, 1933 FOREIGN PATENTS Number Country Date 28,387 Great Britain Dec. 24, 1903 115,961 Germany Dec. 28, 1900 mally out of the machine but movable longitudinally into the machine after the preforming operation and positioned above the preformed blank, and means for imparting a relative movement between said core and die block, whereby the jaws of said die block will press the preformed blank around said core to complete the forming of the tube.

11. In a tube forming machine of the character described, a die block including a pair of pivotally mounted jaws each having an elongated recess therein, a complementary die member including a pair of spaced legs adapted to be received by said recesses, means on said die block to support a tube blank, means to cause a relative movement between said die block and complementary die member toward each other under pressure to thereby preform the tube blank by pressing the sides thereof into the jaw recesses, a core mounted for reciprocation on said die member between the legs thereof and for movement into and out of REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

